Computing devices and communication networks can be utilized to exchange content and other information. In a common application, one computing device (such as a server computing device) can provide a communication to another computing device (such as a client computing device) to cause or provoke an action by the other computing device or a user of the other computing device. The communication may be sent as an email, a web page, an interstitial page, a content item to be displayed on a web page, or the like.
In some scenarios, particular users or computing devices can be selected to receive communications based on prior experience with such communications, and/or based on other criteria. For example, a server computing device may select, from a universe of available users, a subset or “treatment set” of users to whom communications are to be provided. The treatment set can be selected based on heuristics, predicted likelihoods of users to perform a desired action, demographic characteristics of users, and the like. From the perspective of the sender of the communications, the performance of the selection methods (or of the system in general) can be measured in terms of the number or percentage of users performing the desired action after receiving the communications.